Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, ...Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, structural analysis, and optimization). SRE for planning mountain tunnels bridges the gap between the planning on the macro level and the design/analysis on the micro level regarding the risk management of infrastructural systems. A transition from subjective or qualitative description to objective or quantitative quantification of seismic risk is aimed to improve the seismic behavior of the mountain tunnel and thus reduce the associated seismic risk. A new method of systematic SRE for the planning mountain tunnel was presented herein. The method employs extension theory(ET)and an ET-based improved analytical hierarchy process. Additionally, a new risk-classification criterion is proposed to classify and quantify the seismic risk for a planning mountain tunnel. This SRE method is applied to a mountain tunnel in southwest China, using the extension model based on matter element theory and dependent function operation.The reasonability and flexibility of the SRE method for application to the mountain tunnel are illustrated.According to different seismic risk levels and classification criteria, methods and measures for improving the seismic design are proposed, which can reduce the seismic risk and provide a frame of reference for elaborate seismic design.展开更多
In this paper, the phase characteristic disturbance model for baseband direct sequence spread spectrum (DSSS) signal in additive white Gaussian noise (AWGN) environment is established, and the probability density func...In this paper, the phase characteristic disturbance model for baseband direct sequence spread spectrum (DSSS) signal in additive white Gaussian noise (AWGN) environment is established, and the probability density function (PDF) of phase characteristic disturbance is obtained. Then a novel receiver model for baseband DSSS signal based on maximum likelihood (ML) criterion is proposed. The simulation results show that, comparing with correlation scheme, the performance of the proposed method for baseband DSSS signal is 1dB worse in AWGN environment. However, if there is narrow interference in the AWGN environment, the proposed method will show better performance up to 2.5dB, and it has good adaptive resistance to narrowband interference located in different frequency points. This method could be used as an alterative communication scheme for military circumstance when existing strong narrowband interference of various frequencies.展开更多
Probability criterion has its practical significance, and its investment decision-making is determined by the expected discounted wealth. In a complete, standard financial market with short-selling allowed, this paper...Probability criterion has its practical significance, and its investment decision-making is determined by the expected discounted wealth. In a complete, standard financial market with short-selling allowed, this paper probes into the investment decision-making with probability criterion. The upper limit of criterion function is obtained. The corresponding discounted wealth process and hedging portfolio process are provided. Finally, an illustrative example of one-dimensional constant-coefficient financial market is given.展开更多
Finite supply of non-regenerative resources triggers a competition between economic entities or between areas, which requires the ways regarding their utilization with higher levels in science and the standards regard...Finite supply of non-regenerative resources triggers a competition between economic entities or between areas, which requires the ways regarding their utilization with higher levels in science and the standards regarding their use with higher efficiency in economics. To solve a problem of process evaluation in science and of driving force in economics during a process design or a process run for natural resources utilization, a process evaluation parameter originated from natural gas hydrate preparation from a small scale to industrialization scale and the equation of the criterion dependent are introduced to evaluate a variety of processes of natural resources utilization. The analyses indicate that the parameter is relevant to internal undeveloped resources amount change with a stable mass composition in a virtual black box model and external variable market with an implication of process efficiency in economy or of process efficiency of resource utilization and that the parameter has similar features of the thermodynamic state functions. Moreover, the equation of the criterion provided is a difference between the value of the process evaluation parameter at the final state and the value of the process evaluation parameter at the initial state in an actual process, which can be used to determine the direction of development and to judge the size of the driving force in an actual process or an economical run. The provided examples and correlative mathematical description can guide how an identification for the undeveloped resources and a real-time adjustment of dynamic production for the developing resource are done and how decisions regarding resource exploitation, the venture forecasting of capital utilization and updating technology are made. The parameter used itself and the equation of the derived criterion can help by playing a predictive role for selecting the optimal use processes and for designing new process of the natural resource utilization or capital use, and by playing a practical role for adjusting factual production status and for improving the actual process of the utilization of resource or capital in an economic society. Finally, those closed resource systems having accumulation or depletion of the resources or a variable mass such as a decomposition system, a fission system and a biological reproduction system will become possible future research objectives under the guide of this work.展开更多
For the slowly changed environment-range-dependent non-homogeneity, a new statistical space-time adaptive processing algorithm is proposed, which uses the statistical methods, such as Bayes or likelihood criterion to ...For the slowly changed environment-range-dependent non-homogeneity, a new statistical space-time adaptive processing algorithm is proposed, which uses the statistical methods, such as Bayes or likelihood criterion to estimate the approximative covariance matrix in the non-homogeneous condition. According to the statistical characteristics of the space-time snapshot data, via defining the aggregate snapshot data and corresponding events, the conditional probability of the space-time snapshot data which is the effective training data is given, then the weighting coefficients are obtained for the weighting method. The theory analysis indicates that the statistical methods of the Bayes and likelihood criterion for covariance matrix estimation are more reasonable than other methods that estimate the covariance matrix with the use of training data except the detected outliers. The last simulations attest that the proposed algorithms can estimate the covariance in the non-homogeneous condition exactly and have favorable characteristics.展开更多
为对地铁监测数据进行科学分析,在传统“双控”指标分析方法的基础上,引入并改进统计过程控制(statistics process control,SPC)技术,建立新的分析方法。参考基础性国标GB 50068—2018《建筑结构可靠性设计统一标准》中的相关规定,明确...为对地铁监测数据进行科学分析,在传统“双控”指标分析方法的基础上,引入并改进统计过程控制(statistics process control,SPC)技术,建立新的分析方法。参考基础性国标GB 50068—2018《建筑结构可靠性设计统一标准》中的相关规定,明确SPC技术的理论依据3σ准则对应的假设检验显著性水平α=0.27%明显偏小。提出应该以α=5%建立适用于土木工程领域的分析准则,即2σ非连续准则;并将新准则与SPC结合,形成适用于地铁工程建设的监测数据分析方法。最后,基于工程实例验证了新方法的可行性。经研究可以明确:1)引入SPC可以充分利用监测数据,分析出传统分析方法不易识别出的数据变化特征;2)改进SPC技术更加满足地铁工程建设领域的基本要求,对数据的分析判定也更加严格。展开更多
基金financially supported by the National Key Research and Development Program of China (2016YFB1200401)the Western Construction Project of the Ministry of Transport (Grant No. 2015318J29040)
文摘Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, structural analysis, and optimization). SRE for planning mountain tunnels bridges the gap between the planning on the macro level and the design/analysis on the micro level regarding the risk management of infrastructural systems. A transition from subjective or qualitative description to objective or quantitative quantification of seismic risk is aimed to improve the seismic behavior of the mountain tunnel and thus reduce the associated seismic risk. A new method of systematic SRE for the planning mountain tunnel was presented herein. The method employs extension theory(ET)and an ET-based improved analytical hierarchy process. Additionally, a new risk-classification criterion is proposed to classify and quantify the seismic risk for a planning mountain tunnel. This SRE method is applied to a mountain tunnel in southwest China, using the extension model based on matter element theory and dependent function operation.The reasonability and flexibility of the SRE method for application to the mountain tunnel are illustrated.According to different seismic risk levels and classification criteria, methods and measures for improving the seismic design are proposed, which can reduce the seismic risk and provide a frame of reference for elaborate seismic design.
基金supported by the National Basic Research Program (973 Program) of China under Grant No.2007CB310606National Key Technologies R&D Program under Grant No.2009ZX03004-001
文摘In this paper, the phase characteristic disturbance model for baseband direct sequence spread spectrum (DSSS) signal in additive white Gaussian noise (AWGN) environment is established, and the probability density function (PDF) of phase characteristic disturbance is obtained. Then a novel receiver model for baseband DSSS signal based on maximum likelihood (ML) criterion is proposed. The simulation results show that, comparing with correlation scheme, the performance of the proposed method for baseband DSSS signal is 1dB worse in AWGN environment. However, if there is narrow interference in the AWGN environment, the proposed method will show better performance up to 2.5dB, and it has good adaptive resistance to narrowband interference located in different frequency points. This method could be used as an alterative communication scheme for military circumstance when existing strong narrowband interference of various frequencies.
基金This project was supported by the National Natural Science Foundation of China(70171004)Tianjin Natural Science Foundation(013602611).
文摘Probability criterion has its practical significance, and its investment decision-making is determined by the expected discounted wealth. In a complete, standard financial market with short-selling allowed, this paper probes into the investment decision-making with probability criterion. The upper limit of criterion function is obtained. The corresponding discounted wealth process and hedging portfolio process are provided. Finally, an illustrative example of one-dimensional constant-coefficient financial market is given.
文摘Finite supply of non-regenerative resources triggers a competition between economic entities or between areas, which requires the ways regarding their utilization with higher levels in science and the standards regarding their use with higher efficiency in economics. To solve a problem of process evaluation in science and of driving force in economics during a process design or a process run for natural resources utilization, a process evaluation parameter originated from natural gas hydrate preparation from a small scale to industrialization scale and the equation of the criterion dependent are introduced to evaluate a variety of processes of natural resources utilization. The analyses indicate that the parameter is relevant to internal undeveloped resources amount change with a stable mass composition in a virtual black box model and external variable market with an implication of process efficiency in economy or of process efficiency of resource utilization and that the parameter has similar features of the thermodynamic state functions. Moreover, the equation of the criterion provided is a difference between the value of the process evaluation parameter at the final state and the value of the process evaluation parameter at the initial state in an actual process, which can be used to determine the direction of development and to judge the size of the driving force in an actual process or an economical run. The provided examples and correlative mathematical description can guide how an identification for the undeveloped resources and a real-time adjustment of dynamic production for the developing resource are done and how decisions regarding resource exploitation, the venture forecasting of capital utilization and updating technology are made. The parameter used itself and the equation of the derived criterion can help by playing a predictive role for selecting the optimal use processes and for designing new process of the natural resource utilization or capital use, and by playing a practical role for adjusting factual production status and for improving the actual process of the utilization of resource or capital in an economic society. Finally, those closed resource systems having accumulation or depletion of the resources or a variable mass such as a decomposition system, a fission system and a biological reproduction system will become possible future research objectives under the guide of this work.
基金Supported by the National Post-doctor Fundation (No. 20090451251) the Shaanxi Industry Surmount Foundation (2009K08-31) of China
文摘For the slowly changed environment-range-dependent non-homogeneity, a new statistical space-time adaptive processing algorithm is proposed, which uses the statistical methods, such as Bayes or likelihood criterion to estimate the approximative covariance matrix in the non-homogeneous condition. According to the statistical characteristics of the space-time snapshot data, via defining the aggregate snapshot data and corresponding events, the conditional probability of the space-time snapshot data which is the effective training data is given, then the weighting coefficients are obtained for the weighting method. The theory analysis indicates that the statistical methods of the Bayes and likelihood criterion for covariance matrix estimation are more reasonable than other methods that estimate the covariance matrix with the use of training data except the detected outliers. The last simulations attest that the proposed algorithms can estimate the covariance in the non-homogeneous condition exactly and have favorable characteristics.
基金The research was supported by the National Natural Science Foundation of China(Grant Nos.11931018,72101059)Guangdong Natural Science Foundation(Grant No.2020A1515010924).
文摘为对地铁监测数据进行科学分析,在传统“双控”指标分析方法的基础上,引入并改进统计过程控制(statistics process control,SPC)技术,建立新的分析方法。参考基础性国标GB 50068—2018《建筑结构可靠性设计统一标准》中的相关规定,明确SPC技术的理论依据3σ准则对应的假设检验显著性水平α=0.27%明显偏小。提出应该以α=5%建立适用于土木工程领域的分析准则,即2σ非连续准则;并将新准则与SPC结合,形成适用于地铁工程建设的监测数据分析方法。最后,基于工程实例验证了新方法的可行性。经研究可以明确:1)引入SPC可以充分利用监测数据,分析出传统分析方法不易识别出的数据变化特征;2)改进SPC技术更加满足地铁工程建设领域的基本要求,对数据的分析判定也更加严格。